Attachment to machines for forming pulp



March 16, 1954 A. s. VIGER ATTACHMENT TO MACHINES FOR FORMING PULP I 2Sheets-Sheet 1 Filed April 18, 1952 INVENTOR. A l EA/OA/ 5. M652 ,477'OPA/EV5' March 16, 1954 A. s. VIGER ATTACHMENT TO MACHINES FORFORMING PULP Filed April 18. 1952 2 sheets sheet 2 INVEN TOR. A VA/O/V5. W652 Patented Mar. 16, 1954 .aTTAonMENT To MACHINES FOR FORMING PULP7 Avenon'S.'Viger, near Shelton, Wash., assignor to Lamb-Grays HarborWasln, a corporation of Washington Application isms, 1952, Serial No.282,937

' 6 Claims.

The present invention relates toa machine for forming pulp as a blanketupon a large drum or cylinder, usually termed amold, whether at thestage where the pulp isbeing washed or at the stage where the pulp isformed asa blanket of endless length preparatory to forming a web, andspecifically to an attachment to such a machine whereby liquid expressedfrom the web by.adewatering roll is intercepted, and is directed to adischarge point Where it will notreenter the pulp blanket. i

In such an operation water or liquor is expressed from the blanket ofpulp as it passes upwardly from a pulp vat on theperipheral-surface ofthe large mold, by the action of a dewatering roll that presses thepulpblanket; between itself and the molds periphery., Such dewateringrolls express the water by pressure, butin addition such dewateringrolls temporarilycollect'the expressed Water in pockets 1 for 'subsequent discharge. In some instances it is undesirable to permit theliquid so expressed and collected to drip down into the vat, to dilutethe liquor therein, and even when such isnot the, case it is undesirableto permit the expressed and collected water (as the dewatering rollturns over) to drip down again on the uprunning pulp blanket beneath it.Thus in either instance it is desirable to receive the liquid expressedfrom the pulp blanket and collected temporarily in the pockets of thedewateringrolL- and to direct or convey that liquid :for discharge to apoint where at least it will not drip down upon the pulp blanket on themold beneaththedewatering roll, or in other cases to a pointwhere itwill be discharged outside the vat. The, present invention relates toprovisions for socollecting, directing, and dischargingtheexpresseddiquid collected in the dewatering rolls pockets. if

According to one phase of the present inven tion the liquid so collectedinthe pockets of the dewatering roll is extracted or expelled fromthepockets by air-pressure means, such} for instance, as positive pressure,applied toz the pockets before the corresponding peripheral Yportig ofthe dewatering roll again contacts the-pulp blanket, or by meansofsuction or negative pres:- sure applied to the pockets after thewater'has been collected therein, todraw'thenwater irom such pockets.The suctionandthe. positive pressure means are but two instances of air.pressure means for the purpose; and either, orthe two together, may beemployed for the purpose.

In either case it is desirable to provide anintercepting means s'u'ch"asa" trough to receive,

Company, Hoquiam,

and in some cases to collect, such liquid as can not be extracted orexpelled by the air-pressure means, or to collect or to direct away fromthe mold all the liquid in the event the air-pressure means are notemployed, and in the event the return of the liquid to the vat is notobjectionable,

such a trough need be little more than an intercepting apron. It must belocated beneath the dewatering roll and close to the mold, so that itlies generally in the notch between the uprunning lower peripheralportion of the dewatering roll and the uprunning upper peripheralportion of the mold. The present invention is concerned with such anintercepting means, whichever form it may assume, the location of itsdrain if it take the form of a collecting trough, the manner in which itis fixedly located in proper position, yet can move when necessary, andthe mannerin which it is supported with relation to the dewatering roll.

More particularly, because of the necessary location of such a trough,close to the mold, it may at times be impinged by a pulp jam in a mannertending to rotate the trough and to urge it more closely into the notch,or to actually moveit between the dewatering roll and the mold.According to the present invention provision is made for eitherpreventing or permitting such movement, but in either event forminimizing the damage if such tendency should occur.

The objects of the invention are outlined above, and will become moreclearly apparent as this specification progresses.

The present invention comprises the novel attachment to a pulp formingmachine and the novel combination and arrangement of the parts thereof,including the standard parts with relation to the interceptor and waterexpulsion means, and of the latter with respect to one another and withrespect to the standard parts of such a pulp forming machine.

' In the accompanying drawings the invention is shown in tworepresentative forms, as applied to a typical machine. Figure 1 is anisometric view, partially broken away, illustrating one end of theseveral rolls and a trough and other parts which cooperate to the endsindicated above. Figure 2 is a fragmentary end elevation, and Figures isa fragmentary side elevation, of a somewhat modified, apron-like form ofinterceptor.

' The mold is a large drum, perhaps eight feet in'diameter, the endwhereof is represented at I, and its periphery of mesh-like material isillustratedat" l0. .This large moldrotates on jourin the vat. In awashing machine, or if the pulp V is merely to be formed as ablanketif-rom' singlecharge, the blanket is carried round and round.

into and out of the liquor, but where the blanket is the first step inthe manufacture of a" web of indeterminate length, it may bedetached-fromthe mold and carried on thence through various pressing anddrying operations; What happens to the pulp after it passes thedewatering. roll is.

not material to the present invention.

The pulp is usually pressed first between a roll 3 and the periphery ofthe mold i, this r'oll '3b'ei'ngonly slightly" above the level of theliquid within the vat, and secondarily by a dewatering rollindicated ingeneral by the numeral 3*. This'dewat'ering roll has afo'ra-rninousperipheral surface,- indicated at 40, and int'eriorly has a plurality ofscoop-like vanes ll, directed generally' lengthwise and defining aplurality of pockets for the collection and reception of wat'er'expressed from the pulp blanket B through the foramin'ous covering 40.The dewatering roll 4 is mounted upon a shaft :32, supported in abearing 44 in such manner that the roll may be moved bodily towards orfrom the mold l to vary the amount or degree of pressure,- and for otherpurposes.

Thus'the' bearing M is', in a typical'case shown in Figure 1, supportedupon a lever 5 which is pivotallymounted at one end; as indicated at56', upon a bracket 2i which in effect is part of the main frame" orwall-of the vat, and'the opposite end of thelever is' connected to aplunger iii connected'to a pressure'element within a cham berrepresented" at 52 and having the pressure connections 53 and 54"whereby the position of the fever 5 and consequently of the dewateringroll 4 as'a whole may be determined and adjust ed from a distant controlstation; The limit of approach cf the roll" l to the mold may be fixedby an adjustable stop 22, carried by and reacting from the bracket 21'.

The" d'ewatering' roll 4 is preferably closed at its ends by end plateslhan'd in the 'form ofthis invention" which is shown in'Figure 1 theseare provided with holes 45 which are arranged in a common circle, andwhich register with theseveral" pockets" between the vanes 41: At G1 asuction chest registers with-the circle definedby the holesfl-ii and islocated to communicate with theseveral holes in the vicinity of andbeyond the point where the roll 4 contacts with the pulp blanket B. A-similar pressure chest 62 also registers with the circle defined by theholes 45 and is located immediately in advance of the point where theroll 4 contacts with the pulp blanket. By appropriate application ofsuction to the suction chest 6! or of pressure to the pressure chest 62,or both, these chests, both of which are in reasonably tight sealingengagement' with the end plates as, apply pressure, positive ornegative, to the pockets within the interior of the" dewatering roll insucha way as to'insure, to the highest degree possible, the expulsion orextractionof liquid picked up; within these several pockets.I beforethefperipherali por- 4 tion 40 of the roll adjacent such pockets againcontacts with the pulp blanket.

It is clear that these pressure and suction means will to some degreescavenge the several pockets. However, they can draw only from the endsof the pockets, and since the roll 4 is some eight feet long, a greatdeal or liquid spills from the pockets thrdugh the mesh periphery else-Where than at their ends, as the roll l turns over.

Accordingly, it is necessary to provide means for there'ception andcollection of that liquid,

Whether or not the pressure means are used, and

to insure its conveyance to a point where it may be discharged withoutharm, for if this liquid is-permatea mereiy to drip down upon theuprurinih'g pulp blanket beneath it, or upon the 2pressure:rolliiibeneath it, this liquid will again,

in considerable part at least, impregnate the piilpdilanket and willagain have to be expressed.

Accordingly, in oneform of the invention, shown in Figure 1*, I provideatrough 1 which is located below the roll 3,- and more specificallywithin the notch between the uprunning lower periphery of the dewateringroll i and the up running upper periphery orthe mold i". The trough l,thus located, will catch virtually all the liquid that remains in thepockets of the de' watering roll, and, indeed, when it is used thesuction chest 6! and the pressure chest 62 will not be necessary,butmaybe considered as auxiliaries to the trough. The trough ispreferably provided with a soft wiper iii of rubber, for example,contacting the-peri-phery of the dewater ing roll- 4* to wipe off anyliquid that may still tend to cling to it and to guide that liquid backinto the trough. The trough is provided with a drain ll, and itis'preferr'ed' that this drain be located outside the end of the mold lSo located, it would permit the liquid collected in the trough todrainback into the vat 2', but not to drip upon the mold nor upon thepulp blanket B collected on the-molds uprunning periphery. However, ifit is preferred that the collected liquid be discharged elsewhere thanback intothe vat, a flexible hose- (notshown) connected to the drain atH may be provided for the purpose of conducting away and discharging ata proper point the collected liquid.

The trough l is preferably supported upon a bracket T2 which hangs thetrough-from the shaft 42 so that the troughis supported in generalcoaxially of the dewateringrolldi In order that the trough may beheld-steady, a tension member 'll extendsfrom" the trough the fixedsupport, such; for instance; as the wall of the vat 2, but this member'i l 'is of fragile or eadily broken material, s'dth'a't in the event ofan accidental occurren e as will} shortly be described, it can breakreadily and will not then restrain the movementof thet-roughiiIncidentally, the suctionch'es't 6| and the pressure chest 62 mayconveniently be suppert'edfrom the bracket 7-2. Furthermore; it -willbehelpful if the bracket 12 be provided" with an elongated aperture 5'5,through which the shaft fi passes; so tha some radial movemeh t 'ol thebracket" ofthe elcmerits-- supported th'ereby-is"-possible under certainabnormal conditions;

Under normal circumstances the pulp blanket formsi'upoir the peripheryHt or the mold l, and when it is thickenough it contacts the'peripheralsurface of? the" dewatering:v roll: 5,. and likewise or the roll" .3 andbegins to: turn these rolls; As the pulp} blanket builds up inthickness]: the pressure exerted: by; the; pressure chamber at 52vcauses .the dewatering. roll 4 to press with sufiicient pressure. toexpress a large part of the liquid .from the blanket B. This operationcontinues, and .under normal circum stances the collected liquid isexpressed from the pockets in the dewatering roll, is caught inthetrough 'l, or is carried ,off through the suction chest 6i, andthepulp-forming. operation proceeds normally. However, occasionally amassor blob of pulp will collect upon the surface of the blanket and willjaminto the notchbetween theroll 4 and themold I. Since the trough i mustbe located rather closely to the periphery of the mold within thisnotch, such an extraordinary mass or blob of pulp may contact the troughl, and if it does it Will tend strongly to rotate the trough along withthe roll 4 Whenever this occurs the restraining element 14 will break,the slot 15 will permit the bracket 12 and the trough l to approach veryclosely to the periphery of the ,roll 4, and the pressure chamber 52 maybe so formed or controlled that it will permit the roll 4 to move awayfrom the mold I for example into a position shown by the dot-dash linesin the drawing, and so the trough I will pass between the mold I and theroll 4 without causing any great amount of damage. Drain hoses, pressureand suction lines, and the like, connected to the trough or to itssupport, may be flexible and of sufiicient length to permit suchmovement, or may well be arranged to pull ofi when such an event occurs,and so they are not injured. All that is necessary is to shut down themachine temporarily, to clear the jam, and to relocate the parts whichhave been moved, and recommence the operation.

The interceptor shown in Figures 2 and 3 is more nearly of the nature ofan apron, which intercepts the liquid picked up in the interior pocketsof the dewatering roll ,4, and which tends to spill out of them as thesepockets, after riding over the top of the rotative path of the roll 4,incline downwardly again. Here the apronlike interceptor 76 rests at itslower end upon a fixed spray pipe 8, being held thereto by brackets 11,and at its end nearest the mold I and pulp blanket B the interceptor 76is held with its Wiper l pressed against the periphery of the dewateringroll 4 by means of a spring 18 anchored to a collar I9 which encirclesthe shaft 42.

The shaft 42, and thus the dewatering roll 4 as a whole, is in thisarrangement supported upon the outer end of a lever 56, pivotallymounted at 51 upon a bracket 58 carried by the vat wall 2, and theposition of the lever 56, and consequently the pressure with which theroll 4 presses upon the blanket B, is controlled by an adjustabletension element 59, suspending the lever from a suitable overheadsupport In this arrangement there is no provision for expelling orwithdrawing liquid from the pockets within the roll 4. These pocketswill remain full until they pass over the top of the rotative path ofthe dewatering roll, and then as they incline downwardly they will tendto empty through the peripheral mesh 40, and as the roll rotates theliquid will be thrown somewhat inwardly by the centrifugal effect, andwould normally wet the blanket B beneath the dewatering roll 4. However,the interceptor 16 being interposed in position to intercept suchdischarged liquid, and the wiper l0 wiping off any last vestiges thatremain on the surface of the roll 4, all this intercepted liquid willdrain back down the inclined interceptor 16, and will be dischargedinto. the

vat, but clear of the mold l and its blanket B. If discharge back into.the vat were undesirable, it is evident that the interceptor 'IBmightbe formed as a trough to collect rather than todrain off the liquidimmediately, .and it could then be drained oil through drainscorresponding to that shown at H in Figure 1.

Itwill beobservedptoo, thatin this form of the invention the interceptorI6 is so rigidly supported by the spray pipe 8 that it cannot be drawninto. the notchbetween the, peripheries of the roll 4 and mold 'l. Thelever 56 may yield somewhat upwardly, and so relieve pressure on theblanket B in theevent the blanket becomesover- 1y thick or a blobv ofpulp collects thereon, and in such event the raising of the roll 4willcause some raising and tilting of the interceptor 16, but the two willalways remain more or less in the relative positions shown.

It will be realized that one end only of the machine is shown, becauseof the limitations of space, but that the suction chest GI and pressurechest 62, if employed, and in any event the brackets 12 or 1! for thesupport of the interceptors 1 and 15, respectively, would be duplicatedat the opposite end of the machine, and there may be also a duplicatedrain 1!.

I claim as my invention:

1. In a pulp-forming machine, in combination with a mold of largediameter rotative within the pulp vat to collect a peripheral blanket ofpulp and to carry the same to alevel above the liquid within the vat,and with a dewatering roll of small diameter located at the uprunningsideof the molds periphery, means journaling the dewatering roll formovement away from and towards the mold, yieldable biasing meansnormally urging the roll towards and retaining it in operativeengagement with the pulp blanket, to express and to pick up liquid fromthe blanket, a collecting trough, a, draintherefrom to a point locatedwithin the vat but outside-the vertical projection of the mold, meanspivotally mounted coaxially of the dewatering roll, for support of saidtrough to swing upwardly between the mold and the dewatering roll, andeasily ruptured means extending between the trough and a fixed supportto retain the trough in an operative position within the notch definedbetween the uprunning lower periphery of the dewatering roll and theuprunning upper peripheryof the mold, in which operative position thetrough will receive expressed liquid draining from the dewatering roll,but upon rupture of said trough-retaining means said pivotal mountingmeans permitting the trough to swing upwardly between the twoperipheries as they are forced apart, in opposition to the biasingmeans, by the interposition of the trough.

2. A pulp-forming machine as in claim 1, characterized in that thepivotal mounting means of the trough is formed for generally radialapproach of the trough to the dewatering roll in the event of a pulp jamin the notch between the trough and the mold.

3. In a pulp-forming machine, in combination with a pulp vat and with amold of large diameter rotative within the pulp vat to collect aperipheral blanket of pulp and to carry the same to a level above theliquid within the vat, and with a dewatering roll of small diameterlocated at the uprunning side of the molds periphery and cooperatingtherewith by contact with the pulp blanket to express and to pick upliquid from the collected pulp blanket; said dewatering roll ineluding aplurality of longitudinally directed, an g ularly spaced vanes locatedadjacent its periph= cry and defining a plurality of water-collectingpockets, and an e'ndplate closing said pockets but formed with holesadmitting to each pocket and located in a common circle, for drainage;and a suction chest contacting the rolls end plate in position toinclude a number of holes in the vicinity of and immediately beyond theroils point of contact with the pulp" blanket, in the sense of the rollsrotation, to withdraw expressed liquid picked up and collected Withinthe rolis pockets.-

4. In a pulp-forming machine, in corhbinatidn with a pulp vat andwith'amold of large diameter rotative Within the pulp vat to collect a periph=eral blanket of pulp and tocarr'y' the same toa level above the liquidwithin the vat, and with a dewatering roll of small diameter located atthe uprunning side of the molds' periphery and cooperating therewith bycontact with the pulp blanket to express and to pickup liquid from thecollected pulp blanket, said dewate'ring' roll in cluding a plurality oflongitudinally directed, angularly spaced vanes located adjacent itsperiph cry and defining a plurality of water-collecting pockets, and anend plate closiii'gs'aid pocketsbiit formed with holes admitting toeachpocket and located in a commori'ciicldioi dra age;-and anair-pressure chest centaccmg'the i'bllSfit-I plate positionto'includeanumber of holes dn'i'ediateiy in" advance of therows point ofContact with the pulp blanket-in the sense of therolls rotatidn, toexpel undraihed liduid p'icl ied uparidcollected within the roirspockts;I

In a pulp-miningma'chi e; combination with epui vat arid with a mold-013 large diameter lotativ With i if the pulp vat to collect aperiphefal' blanket' of pulp and to carry" thesaihe to" a level above"the liquid-within the vat, arid-with a dewaterihg roll of small diameterlocated atf'the pockets; and an; end plate closing saidpocke'ts butformed with holes admitting to each pocket and located in a commoncircle, for drainage; an airpressure chest contacting the rolls end'plate in position to include a number of holes immediately in advance ofthe rolls point of contact with the pulp blanket, in the sense of therolls rotation, to expel undrained liquid picked up and collected withinthe rolls pockets; and a suction chest contacting the rolls end plate inposition to include a'number of holes in the vicinity of aridimmediately beyond the rolls point of contact with the pulp" blanket, inthe sense of the r'olls rotation, td'withdraw expressed liquid picked upand collected within the rollspockets.

6; In a pulp-formirig machine, in combination with a pulp vat and with amold of large diameter rotative Within the pulp vat to collect aperipheral blanket of pulp and to carry the same to a level above theliquid within the vat, and with a dewa'tering roll of small diameterlocated at the uprunniiig side of the molds periphery and cooperating"therewith by contact with the pulp blanket to e'ikpress and'to pick upliquid from the collected pulp" blanket; said dewater'ing roll in--cluding a plurality of longitudinally directed, angularly spaced vaneslocated adjacent its periphcry and defining a plurality of watelcollecting pockets, and an end plate closing said pockets but formedwith holes admitting to each pocket and located in a condition circle,for drainage; air pressure means acting through saidhole's to expelWater from the rolls pockets in advance of next contact of thecorresponding peripheral portion ,ofthe roll with the'pulpblanket, atrough located in the notch between the uprunriing lower periphery ofthe rolla'ridtheupruhning upper periphery of the mold, to catch water soefipelled, and a from said trough to lead the water caught'therein to apoint where it will not drop back upon the pulp l planliet collected onthe mold.

AVENON s. VIGER.

References Citedin the file of this patent UNITED STATES PATENTS NameDate Crawford June 13', 1933 Numbe

